msg.senderto the Aavegotchi's escrow contract.
msg.sender. Reverts if the reduced amount would be lower than the Aavegotchi's
msg.senderand burns the Aavegotchi NFT. If the second
_tokenIdparameter is different from the first, the burned Aavegotchi also transfers its
experienceto the receiving Aavegotchi in a process known as "essence transfer".